Methods for handling data packets in a digital network of a welding system

ABSTRACT

A method for handling a data packet includes a network device receiving the data packet. The method also includes the network device separating first network layer data of the data packet from message data of the data packet. The message data of the data packet includes a source address represented by less than four bytes, a destination address represented by less than four bytes, and a format identifier. The method includes determining whether the destination address of the message data matches an address of the network device or whether the message data indicates a broadcast message. The method also includes the network device processing the format identifier if the destination address of the message data matches the address of the network device or if the message data indicates the broadcast message. The method includes the network device providing the message data to a second network device and/or other network devices.

BACKGROUND

The invention relates generally to welding systems and, morespecifically, to digital networking within a welding system.

Welding-related devices, such as welding power supplies, welding wirefeeders, welding torches, welding helmets, welding control pendants,welding foot pedals, and other electronic devices, are oftenelectronically coupled together in a welding system. The welding-relateddevices may include network devices that are used to control thedevices, and to facilitate communication between the devices. Forexample, network devices may enable certain devices in the weldingsystem to communicate together using a network medium and a networkprotocol, such as Ethernet, universal serial bus (USB), and/or otherserial communication architectures (e.g., RS-232, RS-422, etc.).Unfortunately, devices in the welding system that are on differentnetworks may be unable to communicate together. Furthermore, certaincommunication architectures may be difficult to implement using certainnetwork devices, such as embedded systems.

BRIEF DESCRIPTION

In one embodiment, a method for handling a data packet includesreceiving, at a network device, the data packet. The method alsoincludes separating, by the network device, first network layer data ofthe data packet from message data of the data packet. The message dataof the data packet includes a source address represented by less thanfour bytes, a destination address represented by less than four bytes,and a format identifier. The method includes determining whether thedestination address of the message data matches an address of thenetwork device or whether the message data indicates a broadcastmessage. The method also includes processing, by the network device, theformat identifier if the destination address of the message data matchesthe address of the network device or if the message data indicates thebroadcast message. The method includes providing, by the network device,the message data to the network device, one or more other networkdevices, or some combination thereof.

In another embodiment, a network device includes a processing deviceconfigured to form message data. The message data includes a sourceaddress represented by less than four bytes, a destination addressrepresented by less than four bytes, and a format identifier. Thenetwork device also includes a network interface device configured toreceive the message data from the processing device, to combine themessage data with network layer data to form a data packet, and toprovide the data packet from the network device to one or more othernetwork devices using one or more network media.

In a further embodiment, a welding system includes a first networkdevice configured to receive a first data packet and to separate firstnetwork layer data of the first data packet from message data of thefirst data packet. The message data of the first data packet includes asource address represented by less than four bytes, a destinationaddress represented by less than four bytes, and a format identifier.The first network device is configured to determine whether thedestination address of the message data matches an address of thenetwork device or whether the message data indicates a broadcastmessage, to process the format identifier if the destination address ofthe message data matches the address of the first network device or ifthe message data indicates the broadcast message, and to package themessage data in a second data packet with second network layer data. Thewelding system also includes a second network device configured toreceive the second data packet if the destination address of the messagedata does not match the address of the first network device or if themessage data indicates the broadcast message.

DRAWINGS

These and other features, aspects, and advantages of the presentinvention will become better understood when the following detaileddescription is read with reference to the accompanying drawings in whichlike characters represent like parts throughout the drawings, wherein:

FIG. 1 is a diagram of an embodiment of a welding system that enablescommunication between network devices in different internal networks ofthe welding system, in accordance with embodiments of the presentdisclosure;

FIG. 2 is a flow chart of an embodiment of a method for assigningaddresses in a welding system having network devices in differentinternal networks, in accordance with embodiments of the presentdisclosure;

FIG. 3 is a block diagram of an embodiment of a network device that mayoperate as a non-routing device, in accordance with embodiments of thepresent disclosure;

FIG. 4 is a block diagram of an embodiment of a network device that mayoperate as a routing device, in accordance with embodiments of thepresent disclosure;

FIG. 5 is a block diagram of an embodiment of message data that may beprovided by one network device to another network device, in accordancewith embodiments of the present disclosure;

FIG. 6 is a block diagram of an embodiment of a message header of themessage data of FIG. 5, in accordance with embodiments of the presentdisclosure;

FIG. 7 is a block diagram of an embodiment of a message payload of themessage data of FIG. 5, in accordance with embodiments of the presentdisclosure;

FIG. 8 is a block diagram of an embodiment of a data packet whichincludes the message data of FIG. 5, in accordance with embodiments ofthe present disclosure; and

FIG. 9 is a flow chart of an embodiment of a method for handling a datapacket in a welding system having network devices in different internalnetworks, in accordance with embodiments of the present disclosure.

DETAILED DESCRIPTION

Turning to the drawings, FIG. 1 is a diagram of an embodiment of awelding system 10 that enables communication between network devices 12in different internal networks of the welding system 10. As may beappreciated, each network device 12 may be an embedded system, such as acomputer system with a dedicated function within the welding system 10.In certain embodiments, one or more network devices 12 may be sensors.Moreover, the network devices 12 may be part of welding-related devicesand may include a processor, electronic components, and/or controlcircuitry to control operation of various tasks. Each network device 12may be part of separate welding-related devices and/or a welding-relateddevice may include more than one network device 12. As illustrated, thewelding system 10 includes network devices 14, 16, 18, 20, 22, 24, 26,28, 30, 32, 34, and 36. All of the network devices 12 may be disposed inone of a welding power supply, welding wire feeder, welding torches,welding helmets, welding control pendants, welding foot pedals, and soforth.

Each of the network devices 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34,and 36 are part of one or more internal networks. Specifically, a firstinternal network 38 includes the network devices 14, 16, and 18. Withinthe internal network 38, the network device 14 may function as a routerfor the internal network 38. As the router, the network device 14controls routing of data to a particular network device 12 within theinternal network 38. Moreover, the network device 14 may also functionas a master device (e.g., root node) for the welding system 10. As themaster node, the network device 14 controls assignment of addresses toall of the network devices 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34,and 36 of the welding system 10.

A second internal network 40 includes the network devices 16, 20, 22,and 24. Within the internal network 40, the network device 16 mayfunction as a router for the internal network 38. Moreover, a thirdinternal network 42 includes the network devices 18 and 26. Within theinternal network 42, the network device 18 may function as a router forthe internal network 42. Furthermore, a fourth internal network 44includes the network devices 22 and 28. Within the internal network 44,the network device 22 may function as a router for the internal network44. A fifth internal network 46 includes the network devices 28, 30, 32,and 34. Within the internal network 46, the network device 28 mayfunction as a router for the internal network 46.

As may be appreciated, the routers may function as bridging devicesbetween different internal networks 36, 38, 40, 42, and 44, therebyfacilitating data transfer between the internal networks 36, 38, 40, 42,and 44. For example, for data to be communicated from the network device30 to the network device 22, the network device 28 provides a bridgebetween the two internal networks 44 and 46. Accordingly, the networkdevice 30 may communicate with the network device 22. In a similarmanner, any of the network devices 12 of the welding system 10 maycommunicate with any other network device 12 of the welding system 10.The internal networks 38, 40, 42, 44, and 46 may be any suitable type ofnetwork, such as Ethernet, universal serial bus (USB), Modbus®, localoperation network (LonWorks), DeviceNet, controller area network (CAN),another serial based network, and so forth.

As illustrated, network connections 48, 50, 52, 54, 56, 58, 60, 62, 64,and 66 are used to connect the network devices 14, 16, 18, 20, 22, 24,26, 28, 30, 32, 34, and 36 together. Moreover, the network connections48, 50, 52, 54, 56, 58, 60, 62, 64, and 66 may be any suitable networkmedia, such as cables, wires, wireless data routes, and so forth. Forexample, the network media may include Ethernet cables, network cables,coax cables, serial communication cables, and so forth. In certainembodiments, the internal networks 38, 40, and 46 represent Ethernetbased networks, while the internal networks 42 and 44 represent USBbased networks. As may be appreciated, the welding system 10 may haveany suitable number of network devices 12 and/or any number of internalnetworks 36, 38, 40, 42, and 44.

FIG. 2 is a flow chart of an embodiment of a method 68 for assigningaddresses in the welding system 10 having network devices 12 indifferent internal networks 36, 38, 40, 42, and 44. As may beappreciated, each network device 12 may be assigned a unique systemaddress for use in communicating within the welding system 10. Incertain embodiments, the address may be formed from approximately onebyte of data. Accordingly, in such an embodiment, 256 differentaddresses may be assigned. As illustrated by the method 68, a networkdevice 12 sends an address request to a router of an internal networkthat the network device 12 is part of (block 70). For example, thenetwork device 30 illustrated in FIG. 1 may send an address request tothe network device 28. In certain embodiments, the network device 12 maybroadcast an address request to all devices of the internal network. Ifthe router is not the master device (e.g., the network device 14) of thewelding system 10 as determined by block 72, the method 68 returns toblock 70 and the router sends the address request to a higher levelrouter. For example, the network device 28 illustrated in FIG. 1 is nota master device of the welding system 10, so the network device 28 sendsthe address request to the network device 22 (e.g., a higher levelrouter). Moreover, the network device 22 is not a master device of thewelding system 10, so the network device 22 sends the address request tothe network device 16. Furthermore, the network device 16 is not amaster device of the welding system 10, so the network device 16 sendsthe address request to the network device 14. As may be appreciated,each of the routers along the path from the network device 30 to thenetwork device 14 may store a record of the path back to the networkdevice 30 (e.g., the originating device). For example, if the internalnetwork 46 is an Ethernet network, the network device 28 may store datain a route table indicating a type of network medium (e.g., Ethernet) bywhich data was received from the network device 30 in conjunction with amedia access control (MAC) address (or some other identifier)corresponding to the network device 30.

If the router is the master device of the welding system 10 (e.g., thenetwork device 14), the master device assigns an address to theoriginating device (block 74). Moreover, the master device stores arecord of the address assignment (block 76). For example, the networkdevice 14 may store an address assignment for the network device 30 inconjunction with a MAC address corresponding to the network device 30.The master device provides the assigned address to the device that themaster device received the request from (block 78). For example, thenetwork device 14 provides the assigned address for the network device30 to the network device 16. A determination is made concerning whetherthe originating device has received the assigned address (block 80).

If the originating device has not received the assigned address, thenetwork device 12 stores the received address assignment in its routingtable (block 82), then returns to block 78. For example, the networkdevice 16 may store an address for the network device 30 that isreceived from the network device 16. Then, the network device 16 mayprovide the address to the network device 22, and so forth. If theoriginating device has received the assigned address, the originatingdevice stores the address assignment (block 84). For example, thenetwork device 30 stores its address assignment after it is received.Accordingly, unique addresses may be assigned to network devices 12 inthe welding system 10.

FIG. 3 is a block diagram of an embodiment of a network device 12 thatmay operate as a non-routing device (e.g., non-router). The networkdevice 12 may include one or more processors 86, memory devices 88,and/or storage devices 90. The processor(s) 86 may be used to executesoftware, such as data processing, welding operation qualitydetermination, welding control, and so forth. Moreover, the processor(s)86 may include one or more microprocessors, such as one or more“general-purpose” microprocessors, one or more special-purposemicroprocessors and/or application specific integrated circuits (ASICS),or some combination thereof. For example, the processor(s) 86 mayinclude one or more reduced instruction set (RISC) processors. Incertain embodiments, the processor(s) 86 may be used to form messagedata for messages sent from the network device 12.

The storage device(s) 90 (e.g., nonvolatile storage) may includeread-only memory (ROM), flash memory, a hard drive, or any othersuitable optical, magnetic, or solid-state storage medium, or acombination thereof. The storage device(s) 90 may store data (e.g.,welding data, address data, control data, message data, etc.),instructions (e.g., software or firmware for determining weldingparameters, etc.), and any other suitable data.

The memory device(s) 88 may include a volatile memory, such as randomaccess memory (RAM), and/or a nonvolatile memory, such as ROM. Thememory device(s) 88 may store a variety of information and may be usedfor various purposes. For example, the memory device(s) 88 may storeprocessor-executable instructions (e.g., firmware or software) for theprocessor(s) 86 to execute, such as instructions for determiningparameters of a welding operation.

The network device 12 also includes a network interface device 92 toenable the network device 12 to communicate with other devices on anetwork. The network interface device 92 may enable communication over aspecific network (e.g., the internal networks 36, 38, 40, 42, and 44),such as Ethernet, USB, another serial communication network, and/or anyother suitable network. Accordingly, the network interface device 92enables the network device 12 to communicate with other network devices12 that are part of the welding system 10. Moreover, in certainembodiments, the network interface device 92 may be configured toreceive message data from the processor(s) 86, to combine the messagedata with network layer data to form a data packet, and to provide thedata packet from the network device 12 to a second network device 12using one or more network mediums.

FIG. 4 is a block diagram of an embodiment of a network device 12 thatmay operate as a routing device (e.g., router). In the illustratedembodiment, the network device 12 may include the one or more processors86, the memory devices 88, and/or the storage devices 90. The networkdevice 12 also includes the network interface device 92 forcommunicating with other devices on a network. Moreover, the networkdevice 12 includes additional network interface devices 94 and 96. Incertain embodiments, the multiple network interface devices 92, 94, and96 enable the network device 12 to receive data from one network (e.g.,the internal networks 36, 38, 40, 42, and 44) using the networkinterface device 92, and to provide data to another network (e.g., theinternal networks 36, 38, 40, 42, and 44) using the network interfacedevices 94 and/or 96. Moreover, in some embodiments, the multiplenetwork interface devices 92, 94, and 96 enable the network device 12 toroute data within a single internal network, such as for routing tothree different network devices 12.

FIG. 5 is a block diagram of an embodiment of message data 98 that maybe provided by one network device 12 to another network device 12. Asused herein, the message data 98 may refer to feedback data,configuration data, data files, any payload, and/or any suitableinformation sent from one device to another. The message data 98includes a message header 100 and a message payload 102. In certainembodiments, the message header 100 may be provided and/or receivedfirst, followed by the message payload 102. Moreover, FIG. 6 is a blockdiagram of an embodiment of the message header 100 of the message data98 of FIG. 5. The message header 100 includes four different portions.Specifically, the message header 100 includes a type 104, a sourceaddress 106, a target address 108 (e.g., destination address), and aformat identifier 110 (e.g., send display data, get data, getconfiguration, etc.). In certain embodiments, the type 104, the sourceaddress 106, the target address 108, and the format identifier 110 areeach one byte such that the message header 100 is four bytes total.Accordingly, with such a message header 100, the message data 98 may bescalable (e.g., having a changeable size) and/or tunnelable (e.g.,encapsulated within another network protocol). In certain embodiments,any of the type 104, the source address 106, the target address 108, andthe format identifier 110 may be larger than one byte, yet still smallenough to be scalable and/or tunnelable in certain networks. Forexample, in certain embodiments, the source address 106 and/or thetarget address 108 may each be greater than one byte and less than fourbytes.

The type 104 may include a six bit tag, such as a wrapping counter usedto represent a total number of messages sent from a network device 12.In certain embodiments, the wrapping counter may skip the value of zero.In such embodiments, the value of zero may identify a broadcast message,or a registered message. Moreover, in some embodiments, not all of thesix bit tag may be used as part of the wrapping counter. For example, anetwork device 12 may choose to wrap 2, 3, 4, or 5 bits, and may use theremaining bits (e.g., high bits, low bits, etc.) to indicate anoriginating message source within the network device (e.g., a specificstate machine or software module). In certain embodiments, responses toa command message having a specific six bit tag may include the same sixbit tag in a response message header of the response.

Furthermore, the type 104 may include a seventh bit used to indicatewhether the message data 98 is a command message or a response message.In certain embodiments, the seventh bit may also be used to indicatewhether the message data 98 is a broadcast message or a registeredmessage. In such embodiments, the six bit tag may be zero to indicatethat the seventh bit represents either a broadcast or a registeredmessage. Accordingly, using the six bit tag and the seventh bit, fourtypes of messages may be used. First, a direct command, which is anunsolicited message sent from a source address to a target address.Second, a direct response, which is a reply sent from a source addressto a requesting target address. Third, a broadcast message, which is amessage from a source address to all addresses. Fourth, a registeredmessage, which is a message identified by a registered message index(e.g., an identification of the registered message of the sendingnetwork device 12). Moreover, the type 104 may include an eighth bitused to indicate whether the message data 98 is intended for the weldingsystem 10 as a whole or for a specific internal network 36, 38, 40, 42,44. In certain embodiments, the eighth bit may be set to the internalnetwork setting for a network device 12 to request an address. Moreover,a routing device may receive such an address request and forward therequest to other internal networks 36, 38, 40, 42, 44 as discussedpreviously.

The source address 106 may be represented by eight bits and may be aunique address that corresponds to a network device 12 within thewelding system 10 from which the message data 98 originates. In certainembodiments, the source address 106 may represent a registered messageindex, for a registered message based system. As may be appreciated, ina registered message based system, a network device 12 may request aregistered message index from a master device before a registeredmessage may be broadcast to other network devices 12. The target address108 may also be represented by eight bits and may be a unique addressthat corresponds to a network device 12 within the welding system 10 forthe message data 98 to be sent to. In certain embodiments, the targetaddress 108 may correspond to a group of network devices 12, such as fora broadcast message. Moreover, the format identifier 110 may berepresented by eight bits and may indicate a format of the data providedby the network device 12 with the target address 108.

As may be appreciated, embodiments in which the source address 106and/or the target address 108 are a single byte, the message header 100may be smaller than in other embodiments in which the source address 106and/or the target address 108 are larger than one byte. Furthermore, thetype 104, the source address 106, the target address 108, and the formatidentifier 110 may be sent and/or received in any suitable order.Moreover, the routable addressing enables the network devices 12 toshare data with other network devices 12 without being aware of networkprotocols or physical communication media of the other network devices12. Furthermore, the network devices 12 communicate without knowingwhether multiple internal networks are involved in the communication.

FIG. 7 is a block diagram of an embodiment of the message payload 102 ofthe message data 98 of FIG. 5. The message payload 102 includes payloaddata 112, a token 114, token data 116, and/or additional data 118.Specifically, the payload data 112 includes data that corresponds to theformat identifier 110. As may be appreciated, the payload data 112 mayinclude other identifiers (e.g., identifiers in addition to the formatidentifier 110) to be performed by the network device 12. In certainembodiments, the token 114 may be an item from a token list. The tokenlist is a list of token values (e.g., unique numbers) that identifyvariables that may be read from or written to a network device 12. Forexample, a token value of six may represent a preset welding voltage.Moreover, in certain embodiments, an engineering unit may be part of thetoken list and may identify an engineering unit that corresponds to thetoken value, thereby reducing an amount of token data 116 communicatedbetween network devices 12. The token data 116 may include any suitabledata that corresponds to the token 114. For example, the token data 116may include a symbol from a symbol list, an engineering unit from anengineering unit list, and/or any other data from a list. Moreover, thesymbol list may include a list of unique numbers identifying specificconcepts, list items, text words, and/or phrases that may not berepresented using a single number. For example, a symbol six mayrepresent “off” and a symbol twenty-three may represent “on.”Furthermore, the engineering unit list may be a list (e.g., or a subsetof the symbol list) that identifies engineering units and scales thatbinary values may be stored in. For example, a “0.1 Volt” engineeringunit may represent 1.0 volts as 10 in binary data. Moreover, any numberof tokens 114 and token data 116 may be included as represented by theadditional data 118. As may be appreciated, the message payload 102 maybe any suitable size enabled by a network transport layer.

FIG. 8 is a block diagram of an embodiment of a data packet 120 whichincludes the message data 98 of FIG. 5. As illustrated, the data packet120 includes network layer header data 122 and the message data 98. Incertain embodiments, the data packet 120 also includes network layerfooter data 124. The network layer header data 122 and/or the networklayer footer data 124 is packaged with the message data 98 by thenetwork device 12 before the network device 12 provides the data packet120 to another network device 12 in the welding system 10 (e.g., usingone of the network interface devices 92, 94, and/or 96). As used herein,the terms “packaged,” “packaging,” and “pack” may refer to any suitablealtering, combining, escaping, framing, and/or fragmenting of themessage data 98. In certain embodiments, the network layer header data122 and/or the network layer footer data 124 may include a MAC addressof the source network device 12 (e.g., the network device 12 sending themessage) and a MAC address of a destination network device 12 (e.g., thenext network device 12 to receive the message). As may be appreciated,the MAC address of the destination network device 12 may not necessarilybe the MAC address of the network device 12 having the target address108 because the message data 98 may get routed through differentinternal networks 36, 38, 40, 42, 44 to reach the network device 12having the target address 108. The network layer header data 122 and/orthe network layer footer data 124 is used to move the message data 98within a network toward the network device 12 having the target address.

FIG. 9 is a flow chart of an embodiment of a method 126 for handling thedata packet 120 in the welding system 10 having the network devices 12in different internal networks 36, 38, 40, 42, 44. A network device 12receives the data packet 120 (block 128). The network device 12separates network layer data (e.g., the network layer header data 122and/or the network layer footer data 124) from the message data 98(block 130). In certain embodiments, the network layer data includes adestination MAC address corresponding to the network device 12. Thenetwork device 12 determines whether the target address 108 (e.g.,destination address) of the message data 98 matches an address of thenetwork device 12 (block 132). If the target address 108 matches theaddress of the network device 12, the network device 12 processes theformat identifier 110 of the message data 98 (block 134).

However, if the target address 108 does not match the address of thenetwork device 12, the network device 12 packs new network layer datawith the same message data 98 it received (block 136). In certainembodiments, the new network layer data includes a source MAC addresscorresponding to the network device 12. The network device 12 thenprovides the data packet 120 to a second network device 12 via a networkmedium (block 138). As may be appreciated, the new network layer datamay include a destination MAC address corresponding to the secondnetwork device 12. Furthermore, in certain embodiments, the secondnetwork device 12 may be a router. The method 126 then returns to block128.

By using the methods and systems described herein, messages may becommunicated between network devices 12 within a welding system 10. Themessages may be provided by one network device 12 and may becommunicated through one or more internal networks 36, 38, 40, 42, 44 toreach a destination network device 12. The addresses used within thewelding system 10 may be single-byte addresses, thereby facilitating alow amount of header data for transmitted messages. Furthermore, themessages may be received by a network device 12 exactly as the messagewas sent from another network device 12.

While only certain features of the invention have been illustrated anddescribed herein, many modifications and changes will occur to thoseskilled in the art. It is, therefore, to be understood that the appendedclaims are intended to cover all such modifications and changes as fallwithin the true spirit of the invention.

The invention claimed is:
 1. A method for handling a data packet in awelding system, comprising: receiving, at a network device, the datapacket, the network device comprising a welding-related device;separating, by the network device, first network layer data of the datapacket from message data of the data packet, wherein the message data ofthe data packet comprises a message header and a message payload, themessage header comprising: a message type; a source address representedby less than four bytes; a destination address represented by less thanfour bytes; and a format identifier indicative of a format of payloaddata of the message data; determining whether the destination address ofthe message data matches an address of the network device or whether themessage data indicates a broadcast message; processing, by the networkdevice, the format identifier in response to determining that thedestination address of the message data matches the address of thenetwork device or the message data indicates the broadcast message; andproviding, by the network device, the message data to a second networkdevice, the second network device comprising a second welding-relateddevice.
 2. The method of claim 1, wherein receiving the data packetcomprises receiving the data packet via a network interface, wherein thenetwork interface comprises an Ethernet interface, a serial interface,or a universal serial bus (USB) interface.
 3. The method of claim 2,wherein providing, by the network device, the message data to the secondnetwork device comprises providing the data packet via a second networkinterface, wherein the second network interface is different than thefirst network interface, and wherein the second network interfacecomprises an Ethernet interface, a serial interface, or a universalserial bus (USB) interface.
 4. The method of claim 1, wherein the sourceaddress comprises only one byte.
 5. The method of claim 1, wherein thedestination address comprises only one byte.
 6. The method of claim 1,wherein the message payload comprises the payload data, one or moretokens, or some combination thereof.
 7. The method of claim 1, whereinthe message header consists of four bytes.
 8. The method of claim 1,wherein the first network layer data comprises a media access control(MAC) address corresponding to the network device.
 9. The method ofclaim 1, wherein providing the message data to the second network devicecomprises packaging the message data with second network layer data. 10.The method of claim 9, wherein the second network layer data comprises afirst MAC address corresponding to the network device and a second MACaddress corresponding to the second network device.
 11. The method ofclaim 1, wherein the message type comprises a wrapping counter used torepresent a total number of messages received by the network device. 12.The method of claim 11, wherein the wrapping counter comprises six bitsor less.
 13. The method of claim 11, wherein determining whether thedestination address of the message data matches an address of thenetwork device or whether the message data indicates a broadcast messagecomprises determining whether the wrapping counter is zero, wherein zeroindicates a broadcast message.
 14. The method of claim 1, wherein themessage type comprises a bit to indicate whether the message data is acommand message or a response message.
 15. The method of claim 1,wherein the message type indicates whether the message data is abroadcast message, a registered message, a command message, a responsemessage, or any combination thereof.
 16. The method of claim 1, whereinthe network device is disposed in one of a welding power supply, awelding wire feeder, a welding torch, a welding helmet, a weldingcontrol pendant, or a welding foot pedal, and the second network deviceis disposed in one of a welding power supply, a welding wire feeder, awelding torch, a welding helmet, a welding control pendant, or a weldingfoot pedal.
 17. The method of claim 1, wherein the message data isprovided to the second network device in response to determining thatthe destination address of the message data does not match the addressof the network device or the message data indicates the broadcastmessage.